US steps up reconnaissance flights targeting IS as third American aid worker kidnapped by the militants is identified

The flights, comprising both manned aircraft and drones, were approved by President Obama over the weekend

Fighters from ISIS marching in Raqqa, Syria (AP) (AP)

The United States is edging closer to a protracted battle across two regions as it began reconnaissance flights over Syria and Iraq in a bid to step up its campaign against IS militants sweeping the region.

It came amid news that a female aid worker has become the third identified American to have been kidnapped and held hostage by IS forces, while a 33-year-old Californian man who travelled to Syria to fight alongside the militant group died in battle over the weekend.

Officials in Washington appear to be moving closer towards a two-pronged attack over the skies of Syria and Iraq. Reconnaissance flights over Syria are understood to have begun on Tuesday ahead of a possible cross-border expansion of its aerial campaign in Iraq. The flights, comprising both manned aircraft and drones, were green-lighted by President Obama over the weekend, sources told AP.

Mr Obama has hitherto been reluctant to implement military action inside Syria limiting airstrikes only to Iraq, but there is a growing urgency to stem the Is advance by targeting their stronghold in the north-east region of Raqqa, where it has been leading the fight in a civil war against the regime of President Bashar al-Assad that has seen more than 200,000 people killed.

In a separate development, it was reported late last night that a 33-year-old Californian who fought alongside IS in Syria has been killed. Douglas McAuthur McCain, of San Diego, is claimed to have been among three foreign jihadis. NBC News claims it has seen photographs of McCain’s passport and of body.

McCain is reported to have entered Syria from Turkey sometime after April this year and is among a handful of Americans that are believed to be fighting with IS.

More than a week ago, journalist James Foley was beheaded by IS militants, after he was kidnapped in 2012. The IS video of Mr Foley’s beheading also showed another of the missing American journalists, Steven Sotloff, and warned he would be killed next if US airstrikes continued. Other US hostages have been held by other militant groups, including Peter Curtis who was recently released by al-Nusra Front, a rival Sunni extremist group, while a US freelance journalist, Austin Tice disappeared in Syria in August 2012 and is believed to be held by the same organization.

On Monday President Assad's foreign minister, Walid al-Moallem, highlighted possible shifting of international alliances in the region by offering Syrian cooperation in the fight against Is. But he warned the US against carrying out air strikes on Syrian territory without consent from Damascus. “Any strike which is not co-ordinated will be considered as aggression,” he said. The White House refused to publicly discuss the flights, but did not deny the report. Spokesman Josh Earnest said the US was willing to take military action to protect US citizens “without regard to international boundaries”. He said: “We are not interested in trying to help the Assad regime,” but acknowledged that “there are a lot of cross-pressures here”.